In the papermaking process, a slurry of cellulose fiber called "stock" containing approximately 991/2% water is delivered by means of pumps to the paper machine headbox. From the headbox, the slurry is distributed to a moving fabric on the paper making machine called a Fourdrinier machine. On the Fourdrinier machine the stock slurry is dewatered from tile 991/2% to approximately 22% by means of suction boxes and/or foil units, etc. During this dewatering period, the papermaker must use whatever equipment and means are available to form the fibers into an acceptable sheet of paper.
There are many devices and versions of the Fourdrinier machine on the market today to make a better sheet at higher speeds. The present invention is unique because it can perform this task at a much lower price while maintaining greater strength in the sheet of paper.
There are several "top wire formers" on the market today that increase speed and make a better looking and flatter sheet. All of them do about the same thing but with different configurations. In order to make the sheet less "two-sided" (i.e. having less differences in appearance and smoothness on the two sides of the paper), these prior art procedures dewater the sheet from both sides (i.e. vacuum units remove the water from above as well as from below the sheet).
In the opinion of many papermakers, dewatering from both sides does make for a less "two-sided" sheet, but at the same time, it reduces the internal bond strength between the fibers in the sheet. When vacuum or foil units exert enough energy into the still tender sheet to remove water from both sides, it also destroys the bonds between fibers which are very important in the early part of the Fourdrinier process in forming a quality paper sheet.
It is an object of this invention to provide a process that increases the bonds between fibers in the sheet, and at the same time produces a sheet that is not "two-sided". It is another object of this invention to provide a process wherein all water is removed from one side of the paper web which is formed between two opposing pressurized sheet-forming fabrics. Still other objects will become apparent from the more detailed description which follows.